The use of computers to play music has created a great interest in techniques of providing a visual accompaniment to the music, known as xe2x80x9ceye candyxe2x80x9d. This interest has been accelerated by the internet and the availability of MP3 audio files which can be downloaded and played on MP3 players, such as WinAmp, Sonique, etc., which are also downloaded. Many of these players are configured to run plug-in visualization programs. Some of these players such as LAVA (Live Audio-Visual Animation), created by the assignee of the present invention, respond in real time to events based on characteristics of the music being played, e.g., transients (such as beats) or sounds in a selected frequency band (such as a high note played by flute).
Typically, the art in the scene consists of shapes and mapped textures which are stored in the memory of the computer. A visualization product disclosed in co-pending application Ser. No. 60/165,059, filed Nov. 12, 1999, entitled xe2x80x9cData Structure and Control Interface for an Event Driven Visual Presentation,xe2x80x9d which is hereby incorporated by reference for all purposes, describes a product allowing editing by a viewer to facilitate substitution of existing scene objects and textures with new objects and textures which may be downloaded from the internet.
A technique for deforming a texture mapped onto a computer generated 3D object based on triggering events detected in a video clip, which may be clip generated in real-time by a video camera, is disclosed in the commonly assigned application Ser. No. 60/165,097, filed Nov. 12, 1999, entitled xe2x80x9cAutomated Acquisition of Video Textures Acquired from a Digital Camera for Mapping to Audio-Driven Deformable Objects,xe2x80x9d which is hereby incorporated by reference for all purposes. Additionally, the scene mapped onto the 3D object can be a video stream, including the video stream which generates the triggering event.
Sophisticated image processing techniques exist which allow images to modified in interesting ways. Often these techniques require the input of many parameters making it tedious to explore the range of manipulations afforded by the techniques. Accordingly, improved techniques of manipulating graphics are required.
According to one aspect of the invention, a method for modifying a texture mapped onto a computer generated 3D object includes the acts of remapping texture coordinates to vertices of the object at discrete times during a control interval generated in response to an external triggering event. The image is interpolated across the polygons associated with vertices. By varying the image coordinates at each vertex interesting transformations of the image are achieved without the cost of modifying each individual pixel of the transformed image.
According to another aspect of the invention, the external triggering event is a change in a characteristic of an audio signal.
According another aspect of the invention, the color of each vertex is changed in response to detected triggering events.
According to another aspect of the invention, a translated or distorted mapped image can be restored by applying a default restoring mapping to the translated or distorted mapped image.
According to another aspect of the invention, remapped texture coordinates generated at different time intervals are blended to smoothly vary the appearance of the remapped images.
Other features and advantages of the invention will be apparent in view of the following detailed description and appended drawings.